The present invention relates to a releasable coupling for securing a tubular member to a further member and to a method for assemblying such a coupling. My above mentioned U.S. Pat. No. 3,822,074 relates to a releasable coupling for tubular members and method for assemblying such coupling to connect tubular members or the like to each other or to connect a tubular member to a pipe connector or the like. In my prior patent the tubular member is inserted into another tubular member having a sufficient inner diameter or in a pipe connector element and a locking pin is inserted into a hole extending substantially tangentially or at a slant relative to the opening into which the tubular member is inserted. There is a certain overlap between the opening and the hole so that the insertion of the locking pin deforms the tubular member to thereby effectively interlock the two elements with each other.
The structure of my prior patent is very effective, especially where gas tied connections are to be established between pipes and the connection is accomplished by relatively simple connecting elements as well as by a minimum of assemblying costs. As mentioned, the insertion of the locking pin results in a deformation of one of the tubular members, thereby providing for a friction lock between the two interconnected elements and the wedging action of the locking pin provides an adequate and effective coupling which is capable, in mechanical respects, to withstand substantial loads in operation while nevertheless being capable of an easy release of the connection.
However, the type of locking pin disclosed in my earlier U.S. Pat. No. 3,822,074 requires, that the coupling member proper as well as the tubular member are of sufficient size to receive the hole for the locking pin and to provide sufficient material that can be deformed by the locking pin. Further, in some of the embodiments of my earlier patent there must be sufficient space externally of the coupling for using a hammer or the like to force the locking pin into the interlocking position.
It is also known to interconnect tubular members by the insertion of a nail type coupling element which extends substantially all around the inner tubular member in a region of overlap between the two tubular members. Such nail type interlocking elements provide an adequate locking against axially effective forces. However, no efficient interlocking against circumferentially effective forces is accomplished by these prior art devices.